During the management of chronic illnesses, the day hospital (DH) serves as a brief and effective alternative to traditional hospitalization, offering access to multidisciplinary care. Indeed, patients can benefit from a range of therapeutic tools provided by a multidisciplinary care team while remaining in their living environment. Numerous structures exist for the management of eating disorders, but primarily for severe cases, often following hospitalization, before transitioning to outpatient care. There is no alternative for the initial management of these patients. The DH for the evaluation and early intervention in recent forms of anorexia nervosa at Maison de Solenn serves as a rapid entry point to specialized care. It allows for a thorough assessment and sustained management of eating disorders. Our hypothesis is that a multidisciplinary, intensive, and early intervention for patients with anorexia nervosa and their families in a day hospital would improve the short, medium, and long-term prognosis of the disease compared to conventional multidisciplinary outpatient care. It would also enhance the family's experience of this pathology and their coping skills.